Dual-substrate capacitive touch panel

ABSTRACT

A capacitive touch panel sequentially has a first glass substrate, a lower touch sensitive layer, a lower insulation ink layer, a lower conductor layer, a lower insulation layer, a lower conductive adhesive layer, a flexible circuit board, a transparent insulation adhesive layer, an upper insulation layer, an upper conductive adhesive layer, an upper conductor layer, an upper insulation ink layer, an upper touch sensitive layer and a second glass substrate. The aforementioned structure allows fabrication of the capacitive touch panel to be separated into a lower panel fabrication process and an upper panel fabrication process. The two independent fabrication processes prevent the capacitive touch panel from being damaged in one of the processes when the process is completed so as to increase the yield in production and further facilitate producing large-size touch panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of Ser. No. 12/803,763,filed Jul. 6, 2010, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention is related to a capacitive touch panel, and moreparticularly to a capacitive touch panel having a relatively high yieldin production and being suitable for manufacture of large-size touchpanel.

2. Description of the Related Art

Existing touch panels can be classified as resistive touch panels andcapacitive touch panels. Recently, the capacitive touch panels becomeincreasingly popular in the market.

With reference to FIG. 3, a conventional touch panel has a first glasssubstrate 61, a lower touch sensitive layer 62, an upper touch sensitivelayer 63, a flexible circuit board 64, a transparent insulation adhesivelayer 65 and a second glass substrate 66. The first glass substrate 61has a top surface and a bottom surface. The upper touch sensitive layer63 and the lower touch sensitive layer 62 are respectively formed on thetop surface and the bottom surface of the first glass substrate 61. Theflexible circuit board 64 is mounted on the top surface of the firstglass substrate 61 and is partially and electrically connected with theupper touch sensitive layer 63. The transparent insulation adhesivelayer 65 is coated on the first glass substrate 61. The second glasssubstrate 66 is covered and bonded on the transparent insulationadhesive layer 65.

However, the conventional technology can only separately forms the uppertouch sensitive layer 63 and the lower touch sensitive layer 62 on thetop and the bottom surfaces of the first glass substrate 61, forexample, forming the upper touch sensitive layer 63 first. Hence, whenthe lower touch sensitive layer 62 is formed subsequently, the completedupper touch sensitive layer 63 is easily scratched or stained during afabrication process of the lower touch. sensitive layer 62. As a result,the production yield is significantly lowered. Because of the low yield,such capacitive touch panels do not aim for large-size touch panel,thereby further limiting the application range thereof Furthermore, asbeing exposed without any protection, the lower touch sensitive layer 62is easily collided and damaged.

BRIEF SUMMARY OF THE INVENTION

An objective of the present invention is to provide a capacitive touchpanel having a relatively high yield in production and being suitablefor manufacture of large-size touch panel.

To achieve the foregoing objective, the capacitive touch panel has afirst glass substrate, a lower touch sensitive layer, a lower insulationink layer, a lower conductor layer, a lower insulation layer, a lowerconductive adhesive layer, a flexible circuit board, a transparentinsulation adhesive layer, an upper insulation layer, an upperconductive adhesive layer, an upper conductor layer, an upper insulationink layer, an upper touch sensitive layer, and a second glass substrate.

The first glass substrate has a first circuit surface.

The lower touch sensitive layer is mounted on the first circuit surfaceof the first glass substrate.

The lower insulation ink layer is mounted on an edge portion of thelower touch sensitive layer so as to let an uncovered portion of thelower touch sensitive layer constitute a touch area, and has a pluralityof lower through slots formed through an portion of the lower insulationink layer covering the edge portion of the lower touch sensitive layerand each filled in with a lower conductive layer.

The lower conductor layer is mounted on the lower insulation ink layerand is electrically connected with the lower touch sensitive layerthrough the lower conductive layers filled in the corresponding lowerthrough slots.

The lower insulation layer is mounted on the lower conductor layer andhas a lower indentation to partially expose the lower conductor layer.

The lower conductive adhesive layer is mounted in the lower indentationof the lower insulation layer to cover the exposed portion of the lowerconductor layer.

The flexible circuit board is mounted on the lower conductive adhesivelayer, extends outwardly beyond the first glass substrate, and iselectrically connected with the lower touch sensitive layer through thelower conductive adhesive layer and the lower conductive layers in thecorresponding lower through slots.

The transparent insulation adhesive layer is mounted on the touch areaand the lower insulation layer.

The upper insulation layer is mounted on the transparent insulationadhesive layer and has an upper indentation to expose the flexiblecircuit board.

The upper conductive adhesive layer is mounted in the upper indentationof the upper insulation layer to contact with the flexible circuitboard.

The upper conductor layer is mounted on the upper conductive adhesivelayer and the upper insulation layer.

The upper insulation ink layer is mounted on the upper conductor layer,and has a plurality of upper through slots formed through the upperinsulation ink layer and each filled in with a upper conductive layerhaving a color identical to that of the upper insulation ink layer.

The upper touch sensitive layer is mounted on the transparent insulationadhesive layer, partially covers the upper insulation ink layer, andcontacts with the upper conductive layers in the corresponding upperthrough slots of the upper insulation ink layer.

The second glass substrate is mounted on the upper touch sensitive layerand the upper insulation ink layer and has a second circuit surface incontact with the upper touch sensitive layer and the upper insulationink layer.

Given the above-mentioned structure of the capacitive touch panel, thelower touch sensitive layer and the upper touch sensitive layerrespectively contact with the first glass substrate and the second glasssubstrate. Upon fabricating the capacitive touch panel, the first glasssubstrate and the second glass substrate can be respectively mounted onthe lower touch sensitive layer and the upper touch sensitive layer withdifferent fabrication processes. As using sheet glass for fabrication ofsingle-sided circuit layer is a mature technique, the resulting yield.in production is relatively high, and the relatively high yield helpsbuild large-size touch panel.

Other objectives, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a capacitive touch panel inaccordance with the present invention;

FIG. 2 is a partial cross-sectional view of the capacitive touch panelin FIG. 1; and

FIG. 3 is a cross-sectional view of a conventional capacitive touchpanel.

DETAILED DESCRIPTION

With reference to FIGS. 1 and 2, a capacitive touch panel has a firstglass substrate 11, a lower touch sensitive layer 12, a lower insulationink layer 13, a lower conductor layer 14, a lower insulation layer 15, alower conductive adhesive layer 16, a flexible circuit board 20, atransparent insulation adhesive layer 30, an upper insulation layer 41,an upper conductive adhesive layer 42, an upper conductor layer 43, anupper insulation ink layer 44, an upper touch sensitive layer 45, asecond glass substrate 46, an upper protection layer 51 and a lowerprotection layer 52.

The first glass substrate 11 has a first circuit surface 111.

The lower touch sensitive layer 12 is mounted on the first circuitsurface 111 of the first glass substrate 11. RI the present embodiment,the lower touch sensitive layer 12 has a lower touch circuit of adouble-layer touch electrode layer, such as an X-axis touch circuit.

The lower insulation ink layer 13 is mounted on an edge portion of thelower touch sensitive layer 12 so that an uncovered portion of the lowertouch sensitive layer 12 constitutes a touch area 131. The lowerinsulation ink layer 13 has a plurality of lower through slots 132formed through an portion thereof covering the edge portion of the lowertouch sensitive layer 12. A lower conductive layer 133 is filled in eachlower through slot 132. In the present embodiment, the lower insulationink layer 13 is formed by printing and baking dark-color ink on thefirst circuit surface 111 of the first glass substrate 11. The portionof the lower insulation ink layer 13 may be printed with or withoutdark-color ink. Accordingly, the lower conductive layer 133 adopts aconductive matter having a color identical to or different from that ofthe lower insulation ink layer 13 as the plurality of lower throughslots 132 are invisible regardless due to all the layers stacked on thelower insulation ink layer 13 and the lower conductive layer 133.

The lower conductor layer 14 is mounted on the lower insulation inklayer 13, and is electrically connected with the lower touch sensitivelayer 12 through the lower conductive layers 133 filled in the lowerthrough slots 132.

The lower insulation layer 15 is mounted on the lower conductor layer 14to prevent the lower conductor layer 14 from being oxidized due toexposure to air. The lower insulation layer 15 has a lower indentation151 to partially expose the lower conductor layer 14. In the presentembodiment, the lower insulation layer 15 is made of a transparentinsulation material.

The lower conductive adhesive layer 16 is mounted in the lowerindentation 151 of the lower insulation layer 15 to cover the exposedportion of the lower conductor layer 14. In the present embodiment, thelower conductive adhesive layer is formed by anisotropic conductive film(ACF) or anisotropic conductive paste (ACP).

Upon fabricating the capacitive touch panel in accordance with thepresent invention, a lower panel fabrication process completing thefirst glass substrate 11, the lower touch sensitive layer 12, the lowerinsulation ink layer 13, the lower conductor layer 14, the lowerinsulation layer 15 and the lower conductive adhesive layer 16 can beconceived.

The flexible circuit board 20 has a top surface 21 and a bottom surface22. The flexible circuit board 20 is mounted on the lower conductiveadhesive layer 16 and the bottom surface 22 is attached on the lowerconductive adhesive layer 16 and extends outwardly beyond the firstglass substrate 11. The flexible circuit board 20 is electricallyconnected with the lower touch sensitive layer 12 through the lowerconductive adhesive layer 16 and the lower conductive layers 133 in thelower through slots 132 of the lower insulation ink layer 13.

The transparent insulation adhesive layer 30 has a thick portion 301 anda thin portion 302. The thick portion 301 is mounted on the touch area131 and the thin portion 302 is mounted on the lower insulation layer15.

The upper insulation layer 41 is mounted on the transparent insulationadhesive layer 30 and has an upper indentation 411 to expose theflexible circuit board 20.

The upper conductive adhesive layer 42 is mounted in the upperindentation 411 of the upper insulation layer 41 to contact with the topsurface 21 of the flexible circuit board 20.

The upper conductor layer 43 is mounted on the upper conductive adhesivelayer 42 and the upper insulation layer 41.

The upper insulation ink layer 44 is mounted on the upper conductorlayer 43 and has a plurality of upper through slots 441 formed throughthe upper insulation ink layer 44. An upper conductive layer 442 isfilled in each upper through slot 441 to contact with the upperconductor layer 43. In the present embodiment, the upper conductivelayer 442 adopts a conductive matter having a color identical to that ofthe upper insulation ink layer 44 to conceal the upper through slots441.

The upper touch sensitive layer 45 is mounted on the transparentinsulation adhesive layer 30, partially covers the upper insulation inklayer 44 and contacts with the upper conductive layer 442 in the upperthrough slots 441 of the upper insulation ink layer 44. Accordingly, theupper touch sensitive layer 45 can be electrically connected with theflexible circuit board 20 through the upper conductive layers 442 in theupper through slots 441 of the upper insulation ink layer 44 and theupper conductive adhesive layer 42. In the present embodiment, the uppertouch sensitive layer 45 is composed of an upper touch circuit of adouble-layer touch electrode layer, such as a Y-axis touch circuit.

The second glass substrate 46 is mounted on the upper touch sensitivelayer 45 and the upper insulation ink layer 44, and has a second circuitsurface 461 in contact with the upper touch sensitive layer 45 and theupper insulation ink layer 44. When viewed from a side opposite to thesecond circuit surface 461 of the second glass substrate 46, the upperinsulation ink layer 44 has a masking effect.

Upon fabricating the capacitive touch panel in accordance with thepresent invention, an upper fabrication process completing, the upperinsulation layer 41, the upper conductive adhesive layer 42, the upperconductor layer 43, the upper insulation ink layer 44, the upper touchsensitive layer 45 and the second glass substrate 46.

With further reference to FIG. 2, the upper protection layer 51 isbonded to the top surface 22 of the flexible circuit board 20 and a sideof the second glass substrate 46 to protect the flexible circuit board20 from directly contacting with a side of the second glass substrate 46when the flexible circuit board 20 is bent. Therefore, the flexiblecircuit board 20 is free from cut and damage done by the second glasssubstrate 46 upon bending.

The lower protection layer 52 is bonded to a side portion of thecapacitive touch panel between the bottom surface 21 of the flexiblecircuit board 20 and the first glass substrate 11 to provide similarprotection to the flexible circuit board 20 as the upper protectionlayer 51 does.

The present invention addresses the following advantages:

Fabrication of the capacitive touch panel of the present invention canbe separated into a lower panel fabrication process and an upper panelfabrication process. According to skill level of the current technology,the yield of using sheet glass to fabricate single-sided circuit layeris high. Hence, the structure of the capacitive touch panel of thepresent invention has a better yield. than conventional capacitive touchpanels in production.

As the yield of the present invention in production is better, thecapacitive touch panel of the present invention can be applied to thefabrication of large-size touch panel, achieving a wider applicationrange.

Even though numerous characteristics and advantages of the presentinvention have been set forth in the foregoing description, togetherwith details of the structure and function of the invention, thedisclosure is illustrative only. Changes may be made in detail,especially in matters of shape, size, and arrangement of parts withinthe principles of the invention to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed.

What is claimed is:
 1. A capacitive touch panel, comprising: a lowerpanel module comprising: a first glass substrate having a first circuitsurface; a lower touch sensitive layer mounted on the first circuitsurface of the first glass substrate; a lower conductor layer mounted onan edge portion of the first glass substrate and electrically connectingthe lower touch sensitive layer; a lower insulation layer mounted on thelower conductor layer and having a lower indentation to partially exposethe lower conductor layer; and a lower conductive adhesive layer mountedin the lower indentation of the lower insulation layer to cover theexposed portion of the lower conductor layer; an upper panel modulecomprising: a second glass substrate having a second circuit surface; anupper touch sensitive layer mounted on the second circuit surface of thesecond glass substrate; an upper insulation ink layer mounted on an edgeportion of the upper touch sensitive layer, and having a plurality ofupper through slots formed through the upper insulation ink layer andeach filled in with a upper conductive layer having a color identical tothat of the upper insulation ink layer; an upper conductor layer mountedon the upper insulation ink layer and electronically connecting theupper touch sensitive layer via the upper conductive layer; an upperinsulation layer mounted on the upper conductor layer and having anupper indentation to partially expose the upper conductor layer; and anupper conductive adhesive layer mounted in the upper indentation of theupper insulation layer; a flexible circuit board mounted on the lowerconductive adhesive layer, extending outwardly beyond the first glasssubstrate, and electrically connected with the lower touch sensitivelayer through the lower conductive adhesive layer; and a transparentinsulation adhesive layer interposed between the upper panel module andthe lower panel module.
 2. The capacitive touch panel as claimed inclaim 1, further comprising an upper protection layer.
 3. The capacitivetouch panel as claimed in claim 2, wherein the flexible circuit boardhas a top surface and a bottom surface, wherein the bottom surface isattached on the lower conductive adhesive layer and the upper protectionlayer is bonded to the top surface of the flexible circuit board and aside of the second glass substrate.
 4. The capacitive touch panel asclaimed in claim 1, further comprising a lower protection layer.
 5. Thecapacitive touch panel as claimed in claim 4, wherein the flexiblecircuit board has a bottom surface, wherein the bottom surface isattached on the lower conductive adhesive layer and the lower protectionlayer is bonded to the bottom surface of the flexible circuit board anda side of the first glass substrate.
 6. The capacitive touch panel asclaimed in claim 3, further comprising a lower protection layer bondedto the bottom surface of the flexible circuit board and a side of thefirst glass substrate.
 7. The capacitive touch panel as claimed in claim1, wherein the lower conductive adhesive layer is formed by at least onechosen from anisotropic conductive film (ACT) and anisotropic conductivepaste (ACP).
 8. A capacitive touch panel, comprising: a lower panelmodule comprising: a first glass substrate having a first circuitsurface; a lower touch sensitive layer mounted on the first circuitsurface of the first glass substrate; a lower conductor layer mounted onan edge portion of the first glass substrate and electrically connectingthe lower touch sensitive layer; a lower insulation layer mounted on thelower conductor layer and having a lower indentation to partially exposethe lower conductor layer; and a lower conductive adhesive layer mountedin the lower indentation of the lower insulation layer to cover theexposed portion of the lower conductor layer; an upper panel modulecomprising: a second glass substrate having a second circuit surface; anupper touch sensitive layer mounted on the second circuit surface of thesecond glass substrate; an upper insulation ink layer mounted on an edgeportion of the upper touch sensitive layer, and having a plurality ofupper through slots formed through the upper insulation ink layer andeach filled in with a upper conductive layer having a color identical tothat of the upper insulation ink layer; an upper conductor layer mountedon the upper insulation ink layer and electronically connecting theupper touch sensitive layer via the upper conductive layer; an upperinsulation layer mounted on the upper conductor layer and having anupper indentation to partially expose the upper conductor layer; and anupper conductive adhesive layer mounted in the upper indentation of theupper insulation layer to cover the exposed portion of the upperconductor layer; a flexible circuit board mounted on the upperconductive adhesive layer and electrically connected with the uppertouch sensitive layer through the upper conductive adhesive laver; and atransparent insulation adhesive layer interposed between the upper panelmodule and the lower panel module.
 9. The capacitive touch panel asclaimed in claim 8, further comprising an upper protection layer. 10.The capacitive touch panel as claimed in claim 9, Wherein the flexiblecircuit board has a top surface, wherein the top surface is configuredon the upper conductive adhesive layer and the upper protection layer isbonded to the top surface of the flexible circuit board and a side ofthe second glass substrate.
 11. The capacitive touch panel as claimed inclaim 8, further comprising a lower protection layer.
 12. The capacitivetouch panel as claimed in claim 11, wherein the flexible circuit boardhas a top surface and a bottom surface, wherein the top surface isconfigured on the upper conductive adhesive layer and the lowerprotection layer is bonded to the bottom surface of the flexible circuitboard and a side of the first glass substrate.
 13. The capacitive touchpanel as claimed in claim 10, further comprising a lower protectionlayer, wherein the flexible circuit hoard has a bottom surface, whereinthe bottom surface is attached on the lower conductive adhesive layer;and the lower protection layer is bonded to the bottom surface of theflexible circuit board and a side of the first glass substrate.
 14. Thecapacitive touch panel as claimed in claim 8, wherein the upperconductive adhesive layer is formed by at least one chosen fromanisotropic conductive film (ACE) and anisotropic conductive paste(ACP).